When
the United States Food and Drug Administration ordered DNA testing
company 23andMe Inc. to withhold certain results from new customers
last December, fresh attention was drawn to the burgeoning home
medical testing industry.

The company had
crossed the line by providing health-related genetic test results —
a big leap from harmless ancestry information, according to Jenny
Geurts, a genetic counselor at Froedtert & The Medical College of
Wisconsin.

"The test
is the same for everyone, no matter what your family history is,"
says Geurts. "There is misunderstanding about what they are
testing for and the limitations of the testing."

Tests that
involve a physician, on the other hand, aim to answer specific
questions about a patient. Geurts is there to remind patients that
even if markers indicate an increased risk of a health problem,
"a genetic test doesn’t mean that’s your destiny."

But would a
person really want to know they are at greater risk for developing
Alzheimer’s or Parkinson’s ? Such information could shape a career
path or make a person decide against having children, or even
contribute to hopelessness or suicide.

"Because
you have these markers — ‘When am I gonna get it?’ — that’s
a really heavy weight to live with," Geurts says. "These are
the kind of conversations I have with people before they have the
test. Once you do the test, you can’t ‘unhear’ the
information."

Meanwhile, some
home tests (pregnancy, HIV and urinary tract infection) give a
consumer a yes-or-no result. Others (cholesterol and various hormones)
produce numbers within a range — it’s best to report the result to
your doctor for interpretation and any follow-up care.

"Most tests
aren’t that definitive," notes Dr. Roy Silverstein, professor
and chair of the department of medicine at Froedtert & MCW.
"One of the biggest dangers is that a normal test result creates
the impression of a get-out-of-jail-free card for an unhealthy diet
and lifestyle."

The
Cost of Testing

Unlike a
test ordered by your doctor, a home test might not be covered by
insurance. Here are the out-of-pocket costs for some popular
test kits (one test per package unless noted).